INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
TO RULE 13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO
RULE 13d-2(a)

Under the Securities Exchange Act of 1934

(Amendment No. 4)

Bloomin'
Brands, Inc.

(Name of Issuer)

Common Stock,
par value $0.01 per share

(Title of Class of Securities)

094235108

(CUSIP Number)

Eleazer Klein, Esq.

Marc Weingarten, Esq.

919 Third Avenue

New York, New York 10022

(212) 756-2000

(Name, Address and Telephone Number of Person

Authorized to Receive Notices and Communications)

April 24,
2018

(Date of Event which Requires

Filing of this Schedule)

If the filing person has previously filed a statement on Schedule
13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), 13d-1(f)
or 13d-1(g), check the following box. [ ]

NOTE: Schedules filed in paper format shall include a signed
original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom copies are to be sent.

(Continued on following pages)

(Page 1 of 5 Pages)

--------------------------

The information required on the remainder of this cover page shall
not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or
otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however,
see the Notes).

CUSIP No. 094235108

SCHEDULE 13D/A

Page 2 of 5 Pages

1

NAME OF REPORTING PERSON

JANA PARTNERS LLC

2

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a) ¨

(b) x

3

SEC USE ONLY

4

SOURCE OF FUNDS

AF

5

CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDING IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)

¨

6

CITIZENSHIP OR PLACE OF ORGANIZATION

Delaware

NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH

7

SOLE VOTING POWER

2,398,045 Shares

8

SHARED VOTING POWER

0

9

SOLE DISPOSITIVE POWER

2,398,045 Shares

10

SHARED DISPOSITIVE POWER

0

11

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH PERSON

2,398,045 Shares

12

CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES

¨

13

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) (see Item
5)

2.6%

14

TYPE OF REPORTING PERSON

IA

CUSIP No. 094235108

SCHEDULE 13D/A

Page 3 of 5 Pages

This Amendment No. 4
("Amendment No. 4") amends and supplements the statement on Schedule 13D filed with the Securities and
Exchange Commission (the "SEC") on November 20, 2017 (the "Original Schedule 13D"), as
amended by Amendment No. 1 filed with the SEC on January 25, 2018 ("Amendment No. 1"), Amendment No. 2 filed
with the SEC on March 1, 2018 ("Amendment No. 2") and Amendment No. 3 filed with the SEC on April 11, 2018
("Amendment No. 3", and together with the Original Schedule 13D, Amendment No. 1, Amendment No. 2 and this
Amendment No. 4, the "Schedule 13D") with respect to the shares ("Shares") of common stock,
par value $0.01 per share, of Bloomin' Brands, Inc., a Delaware corporation (the "Issuer").
Capitalized terms used herein and not otherwise defined in this Amendment No. 4 shall have the meanings set forth in the
Schedule 13D. This Amendment No. 4 amends Items 3, 4, 5(a), (b), (c) and (e) and 7 as set forth below. This is the final
amendment to the Schedule 13D and constitutes an "exit filing" for the Reporting Person.

Item 3.

SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION.

Item 3 of the Schedule 13D is hereby amended and restated in its
entirety as follows:

The 2,398,045 Shares reported herein by the Reporting Person
were acquired at an aggregate purchase price of approximately $27.1 million. Such Shares were acquired with investment funds in
accounts managed by the Reporting Person and margin borrowings described in the following sentence. Such Shares are held by the
investment funds managed by the Reporting Person in commingled margin accounts, which may extend margin credit to the Reporting
Person from time to time, subject to applicable federal margin regulations, stock exchange rules and credit policies. In such instances,
the positions held in the margin accounts are pledged as collateral security for the repayment of debit balances in the account.
The margin accounts bear interest at a rate based upon the broker's call rate from time to time in effect. Because other securities
are held in the margin accounts, it is not possible to determine the amounts, if any, of margin used to purchase the Shares reported
herein.

Item 4.

PURPOSE OF TRANSACTION.

Item 4 of the Schedule 13D is hereby amended and supplemented by
the addition of the following:

The
Reporting Person has sold the Shares of the Issuer reported herein through regular portfolio management activities. The Reporting
Person appreciates the constructive dialogue it has had with the Issuer’s board of directors and management and their commitment
to creating shareholder value.

Item 5.

INTEREST IN SECURITIES OF THE ISSUER.

Items 5(a), (b), (c) and (e) of the Schedule
13D are hereby amended and restated in their entirety as follows:

(a) The aggregate percentage of Shares
reported to be beneficially owned by the Reporting Person is based upon 92,932,752 Shares outstanding as of February 28, 2018,
as reported in the Issuer's Definitive Proxy Statement on Schedule 14A filed with the SEC on March 8, 2018.

As of the close of business on the
date hereof, the Reporting Person may be deemed to beneficially own 2,398,045 Shares, representing approximately 2.6% of the Shares outstanding.

(b) The Reporting Person has sole
voting and dispositive power over 2,398,045 Shares, which power is exercised by the Principal.

(c) Information concerning transactions in the Shares
effected by the Reporting Person since the filing of Amendment No. 3 is set forth in Exhibit H hereto and is incorporated
herein by reference. All of the transactions in Shares listed hereto were effected in the open market through various brokerage
entities.

(e) April 25, 2018

CUSIP No. 094235108

SCHEDULE 13D/A

Page 4 of 5 Pages

Item 7.

MATERIAL TO BE FILED AS EXHIBITS.

Item 7 of the Schedule 13D is hereby amended
and supplemented as follows:

Exhibit H:

Transactions in the Shares effected since the Filing of Amendment No. 3.

CUSIP No. 094235108

SCHEDULE 13D/A

Page 5 of 5 Pages

SIGNATURES

After reasonable inquiry and to the best
of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.